Doctrine extensions slug handlers

[mcbuckets]

I'm trying to setup slugs for my entity that contains two many to one relationships. Both of these relations are on same entity because different user types are presented with generic user class. I differentiate them by role or type field.

On owning BookingRequest side i have:

<field name="slug" column="slug" type="string" nullable="false">
      <gedmo:slug updatable="true" fields="slug, slug" unique="true">
          <gedmo:handler class="Gedmo\Sluggable\Handler\RelativeSlugHandler">
              <gedmo:handler-option name="relationField" value="artist"/>
              <gedmo:handler-option name="relationFieldSlug" value="slug"/>
              <gedmo:handler-option name="separator" value="-"/>
          </gedmo:handler>
          <gedmo:handler class="Gedmo\Sluggable\Handler\RelativeSlugHandler">
              <gedmo:handler-option name="relationField" value="gallery"/>
              <gedmo:handler-option name="relationFieldSlug" value="slug"/>
              <gedmo:handler-option name="separator" value="-"/>
          </gedmo:handler>
      </gedmo:slug>
</field>

In my user entity(artist, gallery) i have:

<field name="slug" column="slug" type="string" nullable="false">
      <gedmo:slug updatable="true" fields="slug" unique="true">
          <gedmo:handler class="Gedmo\Sluggable\Handler\InversedRelativeSlugHandler">
              <gedmo:handler-option name="relationClass" value="App\BookingBundle\Entity\BookingRequest"/>
              <gedmo:handler-option name="mappedBy" value="artist"/>
              <gedmo:handler-option name="inverseSlugField" value="slug"/>
          </gedmo:handler>
          <gedmo:handler class="Gedmo\Sluggable\Handler\InversedRelativeSlugHandler">
              <gedmo:handler-option name="relationClass" value="App\BookingBundle\Entity\BookingRequest"/>
              <gedmo:handler-option name="mappedBy" value="gallery"/>
              <gedmo:handler-option name="inverseSlugField" value="slug"/>
          </gedmo:handler>
      </gedmo:slug>
</field>

I would like to set my BookingRequest slug as combination of artist and gallery slugs but on save i get slugs like -1, -2, -3 and so on.
What am i doing wrong and is this possible?